Detection of SARS-CoV-2 in Milk From COVID-19 Positive Mothers and Follow-Up of Their Infants.

Background: In the current SARS-Coronavirus-2 (SARS-CoV-2) pandemic little is known about SARS-CoV-2 in human milk. It is important to discover if breast milk is a vehicle of infection. Objective: Our aim was to look for the presence of SARS-CoV-2 RNA in the milk of a group of SARS-CoV-2 positive mothers from North-West Italy. Methods: This is a prospective collaborative observational study where samples of human milk from 14 breastfeeding mothers positive for SARS-CoV-2 were collected. A search of viral RNA in breast milk samples was performed by RT-PCR (Real-Time reverse-transcriptase-Polymerase-Chain-Reaction) methodology tested for human milk. All the newborns underwent a clinical follow up during the first month of life or until the finding of two sequential negative swabs. Results: In 13 cases the search for SARS-CoV-2 RNA in milk samples resulted negative and in one case it was positive. Thirteen of the 14 newborns were exclusively breastfed and closely monitored in the first month of life. Clinical outcome was uneventful. Four newborns tested positive for SARS-CoV-2 and were all detected in the first 48 h of life, after the onset of maternal symptoms. Also the clinical course of these 4 infants, including the one who received mother's milk positive for SARS-CoV-2, was uneventful, and all of them became SARS-CoV-2 negative within 6 weeks of life. Conclusion: Our study supports the view that SARS-CoV-2 positive mothers do not expose their newborns to an additional risk of infection by breastfeeding.

Effect of two pasteurization methods on the protein content of human milk.

The Holder method is the recommended pasteurization method for human milk banks, as it ensures the microbiological safety of human milk (HM). The loss of some biologically active milk components, due to the heat treatment, is a main limit to the diffusion of donor HM. High-temperature short-time (HTST) pasteurization may be an alternative to maintain the nutritional and immunological quality of HM. The aim of the present study was to compare the impact of Holder and HTST pasteurization on the HM protein profile. The protein patterns of HTST-treated milk and raw milk were similar. The Holder method modified bile salt-stimulated lipase, lactoferrin and components of the immune system. The HTST method preserved the integrity of bile salt-stimulated lipase, lactoferrin and, to some extent, of IgAs. Holder pasteurization decreased the amount of bile salt-stimulated lipase and inactivated the remaining molecules, while the HTST method did not alter its activity. Pasteurization increased the bioavailable lysine quantity. HTST pasteurization seems to better retain the protein profile and some of the key active components of donor HM.